This proposal seeks partial support for an international conference entitled, "Fourth International Conference on Prevention of Human Cancer: Nutrition and Chemoprevention Controversies". This conference is scheduled to be held June 3-6, 1992, at The Westin La Paloma Resort Hotel in Tucson, AZ. The conference will be sponsored by The University of Arizona Cancer Center & the International Association of Vitamins and Nutritional Oncology (IVANO). Being the fourth in a series, past conferences have been held every three to four years since 1982. The objectives of the conference are: 1) To review, discuss & provide an interdisciplinary forum for the presentation of new data & controversies concerning the dietary & pharmacologic prevention of human cancer; 2) To examine the scientific basis for the development of dietary, nutrient & chemopreventive agent strategies for the prevention of human cancer; 3) To bring together basic & clinical researchers from USA, Europe, Asia & Australia to update recently completed & ongoing human cancer prevention studies throughout the world; and 4) To begin to develop a consensus opinion concerning strategies to prevent breast, colon & other common types of human cancers. Topics of discussion will relate to major controversies concerning strategies for the prevention of human cancers, including: 1) Dietary Intervention vs Dietary Supplementation; 2) Vitamins: Retinoids and Differentiating Agents vs Carotenoids & Antioxidants; 3) Trial Designs: Primary Prevention vs Secondary Prevention vs Tertiary Prevention- 4) Cancer Prevention:Behavior Changes vs Drugs; 5) Colon Cancer: Fat vs Fiber vs Calories vs Nutrient Deficiency; 6) Intermediate Markers of Carcinogenesis: Biochemical vs Molecular; 7) Newer Agents: Drugs vs Natural Products; & 8) International Studies: European vs Japanese vs Chinese vs Australian vs Canadian vs American. Thirty-seven (37) prominent scientists from four different continents (Australia, Asia, Europe, & the USA) have been invited to speak in the broad areas of cell biology, biochemistry, pharmacology, nutrition, epidemiology, & clinical trials. Topics of discussion will include new data and controversies concerning the dietary & pharmacologic prevention of cancer. At least 350 participants are anticipated to attend the upcoming conference in addition to the invited speakers. From critical analysis of the existing data, new ideas & concepts will be generated for future studies concerning the role of nutrition & chemoprevention in management of the malignant human phenotype.